Lovely Leeks

For me, planning a vegetable garden has always been a simple equation: Small suburban garden + a love of cooking = make room for the most expensive vegetables, which is how I started growing leeks.

A leek is basically a gourmet onion plant and often goes for $2 to $3 a pound—that’s a lot of money for a vegetable, half of which is thrown away in cleaning. Ah, but the snow-white stalk that is left after the tough green tops have been removed makes an aromatic underpinning to a sauté, soup, or stew—one that’s more delicate than the flavor an onion imparts. It’s like the difference between the scent of lily of the valley and a ‘Star Gazer’ lily. You can inhale the sweet scent of Convallaria majalis when you hold it up to your nose; you’re bowled over by the bawdy fragrance of ‘Star Gazer’ from a block away.

Leeks (Allium ampeloprasum var. porrum) originate in the Mediterranean basin. Dried specimens and drawings found in Egyptian archeological sites suggest they were part of the region’s diet since 2 B.C., and they are mentioned in the Bible (Numbers 11:5, “We remember the fish we ate in Egypt that cost nothing, the cucumbers, the melons, the leeks, the onions, and the garlic”). The Emperor Nero apparently ate so many to improve his singing voice that he was nicknamed Porophagus, or Leek Eater, which may or may not have been a compliment. By one account, by 640 A.D. leeks had migrated from the Mediterranean and were growing in Britain: Welsh warriors under the command of King Cadwallader stuck leeks in their hats to distinguish themselves from the Saxons in battle. Suffering from nasal congestion? In the Middle Ages, leeks stewed with honey were a remedy for a stuffy nose.

Photos by Patrick Montero

Leeks are remarkably easy to propagate from seed, which is a good thing: It’s difficult to find plants at garden centers, though they’re available as young transplants via catalog and online.

Everything you’ll read about leeks says you can sow them directly into the garden, but leeks generally have a long growing season, ranging from 70 to 120 days, so you’re wise to start them indoors—and early. “I start them in the greenhouse by mid-February or so,” says Ben Saunders, owner of Wabi-Sabi Farm, an organic CSA operation near Des Moines, Iowa. He plants two or three leek seeds to a cell in a high-quality organic potting soil called Cowsmo, from nearby Wisconsin. Then he does something that most of the books I’ve read don’t recommend: In April, he plants those two or three seedlings per cell—now 3-inch plants (the seedlings resemble wheat grass)—into the same hole.

Saunders says that in a perfect world he’d plant the seedlings singly in rows, 6 inches apart. But he has the same problem so many backyard gardeners have—space. “I really need to use space efficiently, and I get a bigger yield this way,” he explains. Makes me wish I’d talked to him before I planted my three rows of leeks like a platoon of soldiers, single file and at attention.

Leeks have an undeserved reputation for being difficult. They’re pretty tough, but they don’t thrive on benign neglect, either. They’re heavy feeders (no problem if you amend your soil with compost to a depth of about 12 inches and feed with compost tea or fish emulsion throughout the season) and need regular watering. Both those factors may affect taste, which is sweeter than other alliums, says William Woys Weaver, Ph.D. He is based in Devon, Pennsylvania, and is an expert on raising and cooking heirloom crops, as his classic Heirloom Vegetable Gardening makes clear. “The soil,” he says, “and how much water they’re getting may affect the amount of sulfur—the sharp chemical that makes you cry when you peel onions—the plant contains.”

Leeks can’t cope with weed competition, either. I weed every time I walk past my raised beds, but I also tuck salt hay grass in and around the young plants as a weed-suppressing mulch.

And then there’s the blanching. The green or blue-green leaves are edible (Weaver recommends them for flavoring stock), but they’re tough and fibrous. To get that nice, white, tender neck, you need to keep at least a couple of inches of a leek plant out of sunlight to prevent it from greening up with chlorophyll. There are a number of different ways to do this, some more labor-intensive than others. Many gardeners use the trench method. Dig a trench 4 to 6 inches deep and plant seedlings in the bottom of the trench, burying them to the point where the leaves separate into a V shape. Make sure the soil isn’t piled so high on either side that sunlight doesn’t reach the tiny seedlings. As the plants grow taller, you simply draw more of the backfill soil around them.

To Saunders, that sounds like too much work. After his leeks are planted, he forms “hills” by pulling soil up around them each time he weeds.

Alternatively, try what Nova Scotia gardener Cliff Seruntine does: Place leek seedlings into cardboard tubes (think toilet paper) when you plant them, burying the tubes slightly into the soil to keep them upright. He drops a pinch of blood meal, a pinch of bone meal, and a pinch of soil into the tubes to nourish the seedlings as they grow. “The tubes make them think it’s dark and encourage them to expand,” says Seruntine, author of Seasons of the Sacred Earth: Following the Old Ways on an Enchanted Homestead.

Or you can do nothing, which is what Weaver does, and still gets enough tender white stem—and stock-worthy green leaves—to make leeks a staple in his cooking.

Leek cultivars are subdivided in a number of ways, but generally they fall into two distinct categories. So-called summer or autumn leeks are intended to be harvested in the late summer or early autumn of the year in which they are planted. The more hardy overwintering leeks, as their name suggests, can be harvested any time, even in the dead of winter, as long as winters are fairly mild and the plants have been protected with a thick layer of mulch, such as dry grass clippings or chopped dried leaves, to prevent the soil from freezing. As a rule of thumb, winter leeks are bluer and stubbier than slender summer leeks, although I’ve found that rules of thumb aren’t reliable (for example, the summer ‘Pandora’ leek is dark blue-green and has a fairly thick shaft, so you might pick it out of a lineup as a winter leek).

Leeks are said to have a few enemies, including nematodes, leaf miners, grasshoppers, mites, and the onion maggot, and to be prone to leaf spot, downy mildew, black mold, and bacterial soft rot, among other things. But I’ve never had any of these problems and neither have any of the leek aficionados I spoke to—one of the reasons we agree that leeks are such a joy to grow. “We’ve had a problem in this area with phytoplasma,” Saunders says, referring to aster yellows disease, an enemy of some Allium crops. “Leafhoppers carry it in their mouths, and it was so warm they rode the thermals up from down south, spreading the disease. It destroyed a lot of garlic but didn’t touch the leeks or other onions. They’re tough.”

Originally published in Organic Gardening magazine, December 2013/January 2014

A Scottish heirloom grown throughout the British Isles that produces thick, short shafts. Cliff Seruntine grows this old standard in his nearly 1-acre Nova Scotia garden, but winters there are so cold he can’t harvest in winter. William Woys Weaver grows it for sentimental reasons—and flavor. “This was the leek my great-grandmother grew,” he says.

'Tadorna'

110 days

A disease-resistant cultivar with thick shafts; overwinters in all but the coldest places